Thanks to the work of many on this mailing list, I've been able to install SID (w/ kernel 2.6.32-5) on my SS4000-E NAS.

Much to my surprise, the performance of the unit is pretty much identical to how it was running the proprietary Falconstor implementation.

hdparm -tT /dev/sda reads :

/dev/sda:

Timing cached reads: 128 MB in 2.00 seconds = 63.93 MB/sec

Timing buffered disk reads: 114 MB in 3.04 seconds = 37.44 MB/sec

The results from hdparm are static across all 4 drives.

Needless to say -- these numbers are atrocious. Max throughput by any means (NFS, FTP, etc.) is about 5MB/sec on writes to the NAS, and 8-9MB/sec on reads from it.

I did come across an earlier post from "Andrushka" that stated 2.6.32 has DMA enabled for "this platform". >From everything I have read, there is no DMA to enable/disable for SATA, but my knowledge is extremely limited in this arena. He does claim that an alternative linux distro installed on the box got 12MB/sec out of the unit.